Turbine engine rotor blades and rotor wheels

ABSTRACT

A rotor wheel and a rotor blade for use in a turbine engine, the rotor wheel and the rotor blade being configured to comprise a connection formed between a root of the rotor blade and an outer radial portion of the rotor wheel that secures the rotor blade to the rotor wheel during operation of the turbine engine; wherein the connection comprises two or more tangential dovetails.

BACKGROUND OF THE INVENTION

This present application relates generally to systems and/or apparatusfor improving the mechanical integrity and/or assembly of the bladeddisk and or rotating parts of turbine engines. (Turbine engines, as usedherein and unless specifically stated otherwise, are meant to includeall types of turbine or rotary engines, including steam turbines, gasturbines, aircraft engines, power generation engines, and others.) Morespecifically, but not by way of limitation, the present applicationrelates to the connection made between the rotor wheel and rotor bladesthat are used in turbine engines.

In general, a steam turbine engine (which, as discussed below, may beused to illustrate an exemplary application of the current invention)includes rows of blades that are axially stacked in stages. Each stageinclude a row of circumferentially-spaced stator blades, which arefixed, and a row of rotor blades, which are attached to the rotor shaftand rotate about a central axis or shaft. In operation, generally, steamfrom a source is expanded through series of axially spaced stages toconvert the energy contained in the steam into the mechanical energy ofthe rotating turbine. As part of this process, rotary mechanical energyfrom the rotating blades is transferred to the rotor shaft though amechanical connection called dovetail. In this manner, the energycontained in the steam is converted into the mechanical energy of therotating shaft. This mechanical energy of the rotating shaft may be usedto drive a generator for producing electricity, compressors, pumps,fans, etc.

Generally, the mechanical connection between the rotor blades and therotor wheel/shaft is a critical one. During operation this connectionmust withstand various mechanical and thermal loads. Prominent amongthese are centrifugal loads due to the rotation and bending loads due tothe differential steam pressure across the stage. In addition to thesesteady state loads, this mechanical connection also endures cyclicalthermo-mechanical loads due to the startup and shutdown processes of theturbine, vibratory loads due to resonance of bucket natural frequencywith excitation frequency, and accumulation of creep strains due toprolonged operation at higher temperature. Material strength degrades athigher temperatures, and mechanical connection between the rotatingblades and rotor wheel must be strong enough to withstand theaforementioned loads at high temperatures.

Per conventional technology, various types of connections have beenemployed between the rotor blades and rotor wheel, for example,tangential entry, axial entry, and radial entry single dovetails.Tangential entry dovetails are easy to manufacture and cost effective,but are limited by centrifugal load carrying capacity. These aregenerally used on smaller blades at high temperature zone and relativelytaller blades at low temperature zone of the turbine engine. The axialentry type dovetails are mainly used where tangential entry dovetailsare prohibited due to higher centrifugal load and/or higher operatingtemperature. Radial entry dovetails (also know as finger type dovetails)are used on taller blades to support very high centrifugal loads. Eventhough both axial entry type dovetails and finger type dovetails areproven to be effective in high-load conditions, complex manufacturingprocesses associated with these kind of dovetails lead to relativelyhigh manufacturing costs.

As a result, there is a need for improved apparatus and/or systemsrelating to a more efficient and cost-effective dovetail connectionsbetween the rotor blades and the rotor wheel of turbine engines.

BRIEF DESCRIPTION OF THE INVENTION

The present application thus describes a rotor wheel and a rotor bladefor use in a turbine engine, the rotor wheel and the rotor blade beingconfigured to comprise a connection formed between a root of the rotorblade and an outer radial portion of the rotor wheel that secures therotor blade to the rotor wheel during operation of the turbine engine;wherein the connection comprises two or more tangential dovetails.

The present application further describes a rotor blade for use in aturbine engine, the rotor blade being configured to make a connectionwith a rotor wheel, the connection being formed between a root of therotor blade and an outer radial portion of the rotor wheel and securingthe rotor blade to the rotor wheel during operation of the turbineengine; wherein the connection comprises two or more tangentialdovetails.

The present application further describes a rotor wheel for use in aturbine engine, the rotor wheel being configured to make a connectionwith a plurality of rotor blades, the connection being formed between aroot of the rotor blades and an outer radial portion of the rotor wheeland securing the rotor blades to the rotor wheel during operation of theturbine engine; wherein the connection comprises two or more tangentialdovetails.

These and other features of the present application will become apparentupon review of the following detailed description of the preferredembodiments when taken in conjunction with the drawings and the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of this invention will be more completelyunderstood and appreciated by careful study of the following moredetailed description of exemplary embodiments of the invention taken inconjunction with the accompanying drawings, in which:

FIG. 1 illustrates a perspective view of a conventional connection.

FIG. 2 illustrates a perspective view of a connection according to anembodiment of the present application.

FIG. 3 illustrates an exploded view of the connection according to anexemplary embodiment of the present application.

FIG. 4 illustrates a perspective view of the connection according toanother exemplary embodiment of the present application.

FIG. 5 illustrates an exploded view of the connection according toanother exemplary embodiment of the present application.

FIG. 6 illustrates a perspective view of the connection according toanother exemplary embodiment of the present application.

DETAILED DESCRIPTION OF THE INVENTION

Illustrative embodiments of the invention now will be described morefully hereinafter with reference to the accompanying drawings, in whichsome, but not all embodiments of the invention are shown. Indeed, theinvention may be embodied in many different forms and should not beconstrued as limited to the embodiments set forth herein; rather, theseembodiments are provided so that this disclosure will satisfy applicablelegal requirements. Like numbers refer to like elements throughout.

Disclosed herein are rotor blades, rotor wheels or rotor shafts(commonly referred to herein as rotor wheels), and/or the connectionsmade between rotor blades and rotor wheels for use in turbine engines.Various embodiments of the application may include a rotor blade and arotor wheel connected to each other via two or more tangentialdovetails. In certain embodiments of the application, each tangentialdovetail may include a dovetail connection between the rotor blade andthe rotor wheel, the connection being substantially brought about bysliding the rotor blade in a tangential direction with respect to therotor wheel. Further, the dovetail connection may include one or moremale projections that interlock within corresponding female grooves.

To describe clearly the invention of the current application, it may benecessary to select terminology that refers to and describes certainmachine components or parts of a turbine engine. Whenever possible,common industry terminology will be used and employed in a mannerconsistent with its accepted meaning. However, it is meant that any suchterminology be given a broad meaning and not narrowly construed suchthat the meaning intended herein and the scope of the appended claims isunreasonably restricted. Those of ordinary skill in the art willappreciate that often certain components may be referred to with severaldifferent names. In addition, what may be described herein as a singlepart may include and be referenced in another context as consisting ofseveral component parts, or, what may be described herein as includingmultiple component parts may be fashioned into and, in some cases,referred to as a single part. As such, in understanding the scope of theinvention described herein, attention should not only be paid to theterminology and description provided, but also to the structure,configuration, function, and/or usage of the component as describedherein.

In addition, several descriptive terms may be used herein. The meaningfor these terms shall include the following definitions. The term “rotorblade”, without further specificity, is a reference to rotating bladesof either a compressor or a turbine, which include both compressor rotorblades and turbine rotor blades. The term “stator blade”, withoutfurther specificity, is a reference the stationary blades of either thecompressor or the turbine, which include both compressor stator bladesand turbine stator blades. The term “blades” will be used herein torefer to either type of blade. Thus, without further specificity, theterm “blades” is inclusive to all type of turbine engine blades,including compressor stator blade, compressor rotor blade, turbinestator blade, and turbine rotor blade. Further, as used herein,“downstream” and “upstream” are terms that indicate a direction relativeto a flow of working fluid through the turbine. As such, the term“downstream” means the direction of the flow, and the term “upstream”means in the opposite direction of the flow through the turbine engine.Related to these terms, the terms “aft” and/or “trailing edge” refer tothe downstream direction, the downstream end and/or in the direction ofthe downstream end of the component being described. And, the terms“forward” or “leading edge” refer to the upstream direction, theupstream end and/or in the direction of the upstream end of thecomponent being described. The term “radial” refers to movement orposition perpendicular to an axis of rotation. It is often required todescribe parts that are at differing radial positions with regard to anaxis. In this case, if a first component resides closer to the axis thana second component, it may be stated herein that the first component is“inboard” or “radially inward” of the second component. If, on the otherhand, the first component resides further from the axis than the secondcomponent, it may be stated herein that the first component is“outboard” or “radially outward” of the second component. The term“axial” refers to movement or position parallel to an axis of rotation.And, the term “circumferential” refers to movement or position around anaxis of rotation. The term “failure” refers to the inability of thecomponent part to meet its intended function, life, or performance.

Referring now to the figures, where the various numbers represent likeparts throughout the several views, FIG. 1 illustrates a perspectiveview of a conventional connection 100 between a rotor wheel 102 and arotor blade 104. The connection 100 may be formed between a root 106 ofthe rotor blade 104 and an outer radial portion 108 of the rotor wheel102. The connection 100 may include a single tangential dovetail 110.Though the connection 100 is generally cost effective in terms ofmanufacturing, the connection 100 may have a limited capacity forwithstanding high centrifugal loads and/or high operating temperatures.Thus, the connection 100 is generally employed in turbine stages wherethe centrifugal loads are relatively low, for example, but not limitedto, high-pressure stages, later intermediate pressure stages and initiallow-pressure stages of the turbine engine. In these stages, the rotorblade 104 may be of short length and consequently, during operation ofthe turbine engine, the centrifugal loads transmitted to the connection100 are low. In the case of later low-pressure stages, where the rotorblade 104 may be of longer length, the centrifugal loads transmitted tothe connection 100 may be higher and, thus, the conventional connection100 is susceptible to failure.

FIG. 2 illustrates a perspective view of a connection 200 in accordancewith an exemplary embodiment of the present application. The connection200 may include the rotor wheel 102 with female dovetail groove and therotor blade 104 with male dovetail projections. In various embodimentsof the present application, the rotor wheel 102 and the rotor blade 104may be used in the compressor or the turbine of the turbine engine. Inan embodiment of the present application, the rotor wheel 102 may be anintegral rotor shaft or a flat disk disposed around a central shaft ofthe turbine engine by means of shrinking onto it or bolting or weldingand plurality of rotor blades 104 are disposed around a circumference ofthe rotor wheel 102. There is no limit on the number of rotor blades 104that may be attached to the rotor wheel 102, the rotor blade 104illustrated in FIG. 2 is only for illustrative purposes and does notlimit the scope of the present application.

The connection 200 is formed between the root 106 of the rotor blade 104and the outer radial portion 108 of the rotor wheel 102. In anembodiment of the present application, the connection 200 may includetwo tangential dovetails 202. In other embodiments of the presentapplication, the connection 200 may include more than two tangentialdovetails 202. The number and design of the tangential dovetails 202 maypartially depend on a length of the rotor blade 104 and the mechanicalloads transmitted to the connection 200 during operation of the turbineengine. In an embodiment of the present application, increasing thenumber of tangential dovetails 202 to two or more reduces the magnitudeof the centrifugal load experienced by individual tangential dovetails202 and also increases a shear area of the hooks that secure theconnection 200 (the hooks are illustrated more clearly in FIGS. 3 and5). Thus, in some embodiments of the present application, the connection200 may be used in low-pressure stages and intermediate-pressure stagesof the turbine engine.

FIG. 3 illustrates an exploded view of the connection 200 in accordancewith an exemplary embodiment of the present application. In anembodiment of the present application, the connection 200 may includetwo internal dovetails. The internal dovetails may include two maleprojections 302, which may be provided on the root 106 of the rotorblade 104. Further, corresponding to the male projections 302, twofemale grooves 304 may be provided in the outer radial portion 108 ofthe rotor wheel 102. In an embodiment of the present application, twodovetail connections may be formed by sliding the rotor blade 104 in asubstantially tangential direction T1 with respect to the rotor wheel102. In various embodiments of the present application, the sliding maybe achieved by a manual or an automated process.

In various embodiments of the present application, the dovetailconnections may include an interlocking between the male projections 302and the corresponding female grooves 304. In an embodiment of thepresent application, the male projections 302 may be formed by wireelectro discharge machining and the female grooves 304 may be formed bya turning operation. However, in other embodiments of the presentapplication, the male projections 302 and the female grooves 304 may bemanufactured by other manufacturing operations such as, but not limitedto, forging, milling, broaching, casting or the like. Further, the maleprojections 302 and the female grooves 304 may be made of a materialsuch as, but not limited to, a metal, an alloy of metals, a composite orthe like. In an embodiment of the present application, the maleprojections 302 and the female grooves 304 may include shot peening toimprove resistance to stress carrion cracking or fatigue.

In an embodiment of the present application, the internal dovetails mayinclude more than two female grooves 304 formed in the rotor wheel 102and the same numbers of corresponding male projections 302 on the rotorblade 104. The female grooves 304 may engage with the corresponding maleprojections 302 to interlock the outer radial portion 108 of the rotorwheel 102 with the root 106 of the rotor blade 104. Thus, the resultinginterlock between the male projections 302 and the female grooves 304may form one or more dovetail connections between the rotor blade 104and the rotor wheel 102.

In certain embodiments of the present application, as shown in FIG. 2,each of the female grooves 304 may extend depth wise in a radiallyinward direction R1 on the outer radial surface of the rotor wheel 102.Moreover, the female grooves 304 may extend width wise in an axialdirection A1. Additionally, the female grooves 304 have a length thatmay extend continuously around the circumference of the rotor wheel 102.The dimensions of the female grooves 304, for example depth and/orwidth, may vary according to the mechanical loads to be endured by theinternal dovetails during the operation of the turbine engine.

In an embodiment of the present application, the interlocking betweenthe male projections 302 and the female grooves 304 may be formed whencertain portions of the male projections 302 overlap with certainportions of the female grooves 304 in the axial direction A1 (and alsoin the radial direction R1). In an embodiment of the presentapplication, each of the male projections 302 may include one or morehooks 306 for engagement with one or more hooks 308 present in thefemale grooves 304. The hooks 306 of the male projection 302 and thehooks 308 of the female groove 304 interlock to hold the rotor blade 104and the rotor wheel 102 together. It will be appreciated that the axialoverlap restricts motion of the blade 104 relative to the wheel 102 inthe radial direction and the radial overlap restricts motion of theblade 104 relative to the wheel 102 in the axial direction. In someembodiments, tangs 310 also may be provided on the rotor blade 102 thatare configured to engage tangs 312 formed one the rotor wheel 102. Asshown, the tangs 310 on the rotor blade 104 overlap in the radialdirection with the tangs 312 in the rotor wheel 102 to restrict themotion of the blade 104 relative to the wheel 102 in the axialdirection.

Further, in certain embodiments of the present application, each of themale projections 302 may be of a substantially symmetrical tree shapewith two or more hooks 306 on both sides of the male projections 302 andcorresponding two or more hooks 308 are provided in the female grooves304.

FIG. 4 illustrates a perspective view of the connection 200 inaccordance with an exemplary embodiment of the present application. Inan embodiment of the present application, a closure section (or “gateopening”) 402 may be disposed on the outer radial portion 108 along thecircumference of the rotor wheel 102. The gate opening 402 may be a slothaving a relatively short circumferential length that is sized so thatit is sufficient to radially insert a turbine blade 104. The gateopening 402 may include a break in the hooks 308 of the female grooves304 that, otherwise, would extend continuously around the rest of thecircumference of the rotor wheel 102. Thus, the gate opening 402 isdevoid of the internal dovetail connections formed by the interlockingof the male projections 302 and the corresponding female grooves 304. Inan embodiment of the present application, the gate opening 402 may beconfigured such that it is used for an insertion of the rotor blade 104in the radially inward direction R1 and then sliding the blade 104 inthe substantially tangential direction T1. Once the rotor blade 104 hasbeen affixed in a position on the circumference of the rotor wheel 102,a subsequent rotor blade may be then inserted and slid in a similarmanner. After the insertion of all the rotor blades is accomplished, aclosure rotor blade (not shown) may be affixed to the gate opening 402of the rotor wheel 102. In an embodiment of the present application, theclosure blade may include a suitable attachment means, such as, but notlimited to, keys or pins. For example, in an embodiment of the presentapplication, one or more cross keys may also be utilized to secure theclosure blade to the adjacent rotor blades 104.

FIG. 5 illustrates an exploded view of a connection 500 in accordancewith another exemplary embodiment of the present application. Theconnection 500 may be disposed between the root 106 of the rotor blade104 and the outer radial portion 108 of the rotor wheel 102. In anembodiment of the present application, the connection 500 may includetwo external dovetails including two male projections 502 provided onthe outer radial portion 108 of the rotor wheel 102. Further, two femalegrooves 504 may be provided in the root 106 of the rotor blade 104corresponding to the male projections 502. In an embodiment of thepresent application, two dovetail connections may be achieved by slidingthe rotor blade 104 in the substantially tangential direction T1 withrespect to the rotor wheel 102. The dovetail connections may include aninterlocking between the male projections 502 and the female grooves504.

In certain embodiments of the present application, the externaldovetails may include more than two male projections 502 formed on therotor wheel 102 and the same number of corresponding female grooves 504formed in the rotor blade 104. The female grooves 504 may engage thecorresponding male projections 502 to interlock the root 106 of therotor blade 104 with the outer radial portion 108 of the rotor wheel102. The resulting interlock between the male projections 502 and thefemale grooves 504 may result in dovetail connections between the rotorblade 104 and the rotor wheel 102.

In certain embodiments of the present application, each of the maleprojections 502 may have a height in the radially outward direction R1from the outer radial portion 108 of the rotor wheel 102. The maleprojections 502 may extend width wise in the axial direction A1.Further, the male projections 502 have a length that may extendcontinuously around the circumference of the rotor wheel 102. Thedimensions of the male projections 502, for example depth and/or width,may vary according to the mechanical loads to be endured by the externaldovetails during the operation of the turbine engine.

In certain embodiments of the present application, the interlockingbetween the male projections 502 with the respective female grooves 504may be formed when certain portions of the male projections 502 overlapwith certain portions of the female grooves 504 in the axial directionA1. In an embodiment of the present application, each male projection502 may include one or more hooks 506 for engagement with hooks 508 inthe respective female groove 504. The hooks 506 of the male projection502 and the hooks 508 of the female projection 504 may interlock to formthe external dovetail connection. It will be appreciated that the axialoverlap restricts motion of the blade 104 relative to the wheel 102 inthe radial direction and the radial overlap restricts motion of theblade 104 relative to the wheel 102 in the axial direction. In someembodiments, tangs 510 also may be provided on the rotor blade 102 thatengage tangs 512 formed on the rotor wheel 102. As shown, the tangs 510on the rotor blade 104 overlap in the radial direction with the tangs512 in the rotor wheel 102 to restrict the motion of the blade 104relative to the wheel 102 in the axial direction.

FIG. 6 illustrates a perspective view of the connection 500 inaccordance with another exemplary embodiment of the present application.The connection 500 may include two tangential dovetails. In variousembodiments of the present application, the connection 500 may includemore than two tangential dovetails.

In an embodiment of the present application, a closure section (or “gateopening”) 602 may be disposed on the outer radial portion 108 along thecircumference of the rotor wheel 102. The gate opening 602 may be a slotof a relatively short circumferential length along the rotor wheel 102that is sufficient to radially insert a blade. The gate opening mayinclude a break in the hooks 506 of the male projections 502 which,otherwise, extend continuously around the rest of the circumference ofthe rotor wheel 102. Thus, the gate opening 602 is devoid of anydovetail connections formed by the interlocking of the male projections502 and the corresponding female grooves 504. In an embodiment of thepresent application, the gate opening 602 may be configured such that itis used for the insertion of the rotor blade 104 in the radial directionR1 and then sliding the blade 104 in the substantially tangentialdirection T1. Once the rotor blade 104 has been affixed in a position onthe circumference of the rotor wheel 102, a subsequent rotor blade 104may be inserted and slid onto the wheel 102 in a similar manner. Afterthe insertion of all the rotor blades is accomplished in this manner, aclosure rotor blade (not shown) may be affixed to the closure section602 of the rotor wheel 102. In an embodiment of the present application,the closure blade may include a suitable attachment means, for example,but not limited to, keys or pins. For example, in an embodiment of thepresent application, one or more cross keys may also be utilized tosecure the closure blade to the adjacent rotor blades 104.

As one of ordinary skill in the art will appreciate, the many varyingfeatures and configurations described above in relation to the severalexemplary embodiments may be further selectively applied to form theother possible embodiments of the present application. For the sake ofbrevity and taking into account the abilities of one of ordinary skillin the art, all of the possible iterations is not provided or discussedin detail, though all combinations and possible embodiments embraced bythe several claims below or otherwise are intended to be part of theinstant application. In addition, from the above description of severalexemplary embodiments of the invention, those skilled in the art willperceive improvements, changes and modifications. Such improvements,changes and modifications within the skill of the art are also intendedto be covered by the appended claims. Further, it should be apparentthat the foregoing relates only to the described embodiments of thepresent application and that numerous changes and modifications may bemade herein without departing from the spirit and scope of theapplication as defined by the following claims and the equivalentsthereof.

1. A rotor wheel and a rotor blade for use in a turbine engine, therotor wheel and the rotor blade being configured to comprise aconnection formed between a root of the rotor blade and an outer radialportion of the rotor wheel that secures the rotor blade to the rotorwheel during operation of the turbine engine; wherein the connectioncomprises two or more tangential dovetails.
 2. The rotor wheel and rotorblade of claim 1, wherein: the tangential dovetail comprises a dovetailconnection between the rotor blade and rotor wheel that is substantiallyengaged by sliding the rotor blade tangentially in relation to the rotorwheel; and the dovetail connection comprises a male projection thatinterlocks within a female groove.
 3. The rotor wheel and rotor blade ofclaim 2, wherein the connection comprises a plurality of internaldovetails, the internal dovetails comprising two or more female groovesformed in the rotor wheel engaging the same number of corresponding maleprojections formed on the root of the rotor blade.
 4. The rotor wheeland rotor blade of claim 3, wherein the female grooves are grooves that,depth wise, extend radially inward into an outer radial surface of therotor wheel, width wise, extend axially a relatively short distance,and, length wise, extend circumferentially around most of thecircumference of the rotor wheel in a continuous manner.
 5. The rotorwheel and rotor blade of claim 2, wherein the connection comprises aplurality of external dovetails, the external dovetails comprising twoor more male projections formed on the rotor wheel engaging the samenumber of corresponding female grooves formed in the root of the rotorblade.
 6. The rotor wheel and rotor blade of claim 5, wherein the maleprojections are projections that, height wise, extend radially outwardfrom an outer radial surface of the rotor wheel, width wise, extendaxially a relatively short distance, and, length wise, extendcircumferentially around most of the circumference of the rotor wheel ina continuous manner.
 7. The rotor wheel and rotor blade of claim 2,wherein the interlock is formed via portions of the male projection thatoverlap in axial and radial direction with portions of the femalegroove.
 8. The rotor wheel and rotor blade of claim 7, wherein the rotorwheel further comprises a closure section along a relatively narrowsection of the circumference of the rotor wheel, the closure sectionbeing configured such that the interlock of the dovetail connection isnot present.
 9. The rotor wheel and rotor blade of claim 2, wherein themale projection comprises at least one hook that engages at least onehook in the female grove, thereby forming the interlock of the dovetailconnection.
 10. The rotor wheel and rotor blade of claim 9, wherein themale projection comprises a substantially symmetrical tree shape, thetree shape having at least two hooks on each side.
 11. A rotor blade foruse in a turbine engine, the rotor blade being configured to make aconnection with a rotor wheel, the connection being formed between aroot of the rotor blade and an outer radial portion of the rotor wheeland securing the rotor blade to the rotor wheel during operation of theturbine engine; wherein the connection comprises two or more tangentialdovetails.
 12. The rotor blade of claim 11, wherein: the tangentialdovetail comprises a dovetail connection between the rotor blade androtor wheel that is substantially engaged by sliding the rotor bladetangentially in relation to the rotor wheel; and the dovetail connectioncomprises a male projection that interlocks within a female groove. 13.The rotor blade of claim 12, wherein the connection comprises aplurality of internal dovetails, the internal dovetails comprising twoor more female grooves formed in the rotor wheel that engage the samenumber of corresponding male projections formed on the root of the rotorblade.
 14. The rotor blade of claim 12, wherein the connection comprisesa plurality of external dovetails, the external dovetails comprising twoor more male projections formed on the rotor wheel that engage the samenumber of corresponding female grooves formed in the root of the rotorblade.
 15. The rotor blade of claim 12, wherein the interlock is formedvia portions of the male projection that overlap in the axial and radialdirection with portions of the female groove.
 16. The rotor blade ofclaim 15, wherein the male projection comprises at least one hook thatengages at least one hook in the female grove, thereby forming theinterlock of the dovetail connection.
 17. A rotor wheel for use in aturbine engine, the rotor wheel being configured to make a connectionwith a plurality of rotor blades, the connection being formed between aroot of the rotor blades and an outer radial portion of the rotor wheeland securing the rotor blades to the rotor wheel during operation of theturbine engine; wherein the connection comprises two or more tangentialdovetails.
 18. The rotor wheel of claim 17, wherein: the tangentialdovetail comprises a dovetail connection between the rotor blades androtor wheel that is substantially engaged by sliding the rotor bladestangentially in relation to the rotor wheel; and the dovetail connectioncomprises a male projection that interlocks within a female groove. 19.The rotor wheel of claim 18, wherein the connection comprises aplurality of internal dovetails, the internal dovetails comprising twoor more female grooves formed in the rotor wheel that engage the samenumber of corresponding male projections formed on the root of the rotorblades.
 20. The rotor wheel of claim 19, wherein the female grooves aregrooves that, depth wise, extend radially inward into an outer radialsurface of the rotor wheel, width wise, extend axially a relativelyshort distance, and, length wise, extend circumferentially around mostof the circumference of the rotor wheel in a continuous manner.
 21. Therotor wheel of claim 18, wherein the connection comprises a plurality ofexternal dovetails, the external dovetails comprising two or more maleprojections formed on the rotor wheel that engage the same number ofcorresponding female grooves formed in the root of the rotor blades. 22.The rotor wheel of claim 21, wherein the male projections areprojections that, height wise, extend radially outward from an outerradial surface of the rotor wheel, width wise, extend axially arelatively short distance, and, length wise, extend circumferentiallyaround most of the circumference of the rotor wheel in a continuousmanner.
 23. The rotor wheel of claim 18, wherein the interlock is formedvia portions of the male projection that overlap in the axial and radialdirection with portions of the female groove.
 24. The rotor wheel ofclaim 23, wherein the male projection comprises at least one hook thatengages at least one hook in the female grove, thereby forming theinterlock of the dovetail connection, and wherein the rotor wheelfurther comprises a closure section along a relatively narrow section ofthe circumference of the rotor wheel, the closure section beingconfigured such that the interlock of the dovetail connection is notpresent.